One example of a surface to be cleaned is a roadway surface on which accumulated some snow and/or ice (which are hereafter generically referred to in a non-limitative manner as “frozen water materials”). This is traditionally done using a rigid blade having a lowermost edge that is in engagement with the roadway surface. The blade is attached to a vehicle, for instance a truck or the like, travelling over the roadway surface. A blade is often relatively large so as to maximize the width of the surface cleaned in a single pass. Such concept, however, assumes that the roadway surface is perfectly smooth, flat and free of obstructions. In practice, roadway surfaces are not. For instance, the surface height profile often varies irregularly from one end of the lowermost edge of the blade to the other and the surface height profile varies all the time as the blade moves thereon. The lowermost edge is therefore not always fully in engagement with the roadway surface over its entire length, with the result that some frozen water materials tend to remain on the roadway surface at various locations, especially where the surface height is the lowest compared to the immediate surrounding areas. The efficiency of the cleaning is thus reduced.
Road maintenance operators must often use de-icing chemicals to melt the remaining frozen water materials so as to complete the cleaning. The amounts of de-icing chemicals are generally inversely proportional to efficiency of the cleaning. Thus, if the cleaning is inefficient, more de-icing chemicals are required. This has a direct impact on the operating costs and increases the footprint on the environment.
Different approaches have been suggested over the years for mitigating the difficulties experienced with fully-rigid snowplow blades. One approach is presented for instance in Swiss Patent No. 416,708 granted 15 Jul. 1966. This patent uses a series of spring-biased movable plates on the lowermost edge of the blade. Similar arrangements are disclosed for instance in U.S. Pat. No. 3,400,475 granted 10 Sep. 1968, in Canadian Patent No. 2,423,830 granted 10 Feb. 2004 and in U.S. Pat. No. 7,467,485 granted 23 Dec. 2008.
Another approach is to use a series of plates on the lowermost edge of the blade where the plates are resiliently attached to the rest of the blade. Examples are shown in U.S. Pat. No. 520,479 granted 29 May 1894 and in U.S. Pat. No. 5,743,032 granted 28 Apr. 1998.
Canadian Patent No. 2,796,157 issued on 13 Aug. 2013 to Jimmy Vigneault discloses a scraper blade device where ground-engaging blade segments are independently slidingly movable, in an up and down movement, out of alignment with reference to the bottom edge of the other blade segments so as to keep an optimized contact with the surface to be cleaned in spite of the various height variations across the width resulting from irregularities encountered on the surface as the scraper blade device moves thereon. The bottom edge of the blade segments can also be temporarily pivoted towards a tripped reclined position upon impact with an obstruction on the surface to be cleaned so as to mitigate damages to the blade segments and/or to the surface to be cleaned. Canadian Patent No. 2,796,157 is hereby incorporated by reference in its entirety.
In general, it is often desirable to minimize the total number of blade segments in a scraper blade device so as to lower the overall manufacturing costs and complexity. On the other hand, increasing the number of blade segments can increase the efficiency of the cleaning since using more adjacent blade segments across the width of the scraper blade device means that each blade segment will be narrower in width. Narrower blade segments can follow the irregularities on the surface more closely. However, increasing the number of blade segments will require additional components and/or labor. A compromise must be found between the desired efficiency and these factors.
There is always some room for further improvements in this area of technology and improvements in overall efficiency of the cleaning are particularly desirable.